Thin and/or thick film conductor inks, incorporating metals such as gold, copper, silver and the like, are applied as contacts on microelectronic devices. A conductor ink is a mixture of extremely fine particles of metal and glass dispersed in organic and inorganic carriers. Upon firing of the conductor ink, the volatile carrier evaporates and a metal contact incorporating glass is deposited on the microelectronic substrate. To prevent premature device failure, the conductor ink must be fired within a limited temperature range to insure proper bonding of the contact to the metallic or non-metallic substrate. To determine the proper firing temperature, the conductor ink has to be removed from the substrate without damaging the substrate. Scribing and breaking the substrate at the point of adhesion followed by viewing the substrate under a scanning electronic microscope (SEM) is a known method to determine the adhesion of the metal. However, this method is not always possible and may damage the structure of the glass binder layer of the contact on the substrate.
Thus, a method and apparatus which can leach the contacting metal out of the fired conductor ink and away from the metallic or non-metallic substrate to reveal the interface (binder layer to metal phase) microstructure would be highly desirable.